Insect repellent



Patented Aug. 10, 1937 TED STATES PATENT OFFICE- Gulf Research & Development Company, Pittsburgh, Par, a corporation of Delaware No Drawing.

Application March 16, 1936, Serial No. 69,218

6 Claims. (Cl. rev-22) This invention relates to insect repellents and more particularly it relates to an improved insect repellent comprising a petroleum fraction containing an added substance selected from the 5 class consisting of diethylene glycol monobutyl ether and'diethylene glycol monoethyl ether acetate; and it further comprises a method of manufacturing such a repellent; all as more fully hereinafter set forth and as claimed.

l Insect repellents difier from insecticides in that they are not particularly toxic to insects and for the most part they employ a petroleum base to which something is added repulsive to insects. In order to give a composition of a particular 15 consistence for a particular use, the consistency of both the base and of the addition must be considered. For instance when the repellent is to a lotion a petroleum fraction is used which in viscosity is somewhere intermediate between those mentioned above, such as a white petroleum oil of the variety usually known as medicinal oils.

30 In the past, pine oil has been considered one of the better insect repellents suitable for incorporation in .petroleum bases. However, this compound is objectionable by reason of its strong odor which is oifensive not only to insects but to human beings. When used in repellents applied to dairy cattle, pine oil frequently taints the milk and thus ruins it for human consumption. I have discovered that diethylene glycol monobutyl ether and diethylene glycol monoethyl 4O ether acetate are excellent insect repellents hav ing certain advantages over prior repellents when incorporated in petroleum bases. Both are prac tically odorless and both are sumciently soluble in petroleum oils for the present purposes. 45 These compounds when incorporated in petro-' leum bases are'substantially odorless in concentrations up to 15 per cent.' Repellence towards flies and other insects is definitely exhibited when either of these compounds is present in petroleum 50 base preparations concentrations of 5 per cent or over. I t

a I find that diethylene glycol monobutyl ether is more soluble in heavy oils, jellies and waxes than is diethylene glycol monoethyl ether acetate 55 and this property makes it more suitable for incorporation with heavier petroleum fractions. However, diethylene glycol monoethyl ether acetate is sufliciently soluble in light oils to make its useadvantageous when the repellent composition is to be given the consistency of a liquid lotion or a liquid spray. For instance, diethylene glycol monoethyl ether acetate is soluble up to 5 per cent by volume in petroleum oils having a viscosity of 1-00 at 100 F. as determined with the Saybolt universal viscosimeter. Diethylene glycol monobutyl ether is entirely, miscible with petroleum oils having a viscosity of-100 S. U. V. at 100 F. audit is soluble in petroleum jellies such as petrolatum in concentrations of per centwby volume or over. it is slightly less soluble. but'sufficient amounts may be incorporated with such waxes to impart a definite repellence to the mixture. In an advantageous embodiment of my invention I have prepared an excellent repellent spray particularly suitable for application to livestock by adding 8 per cent by volume of diethylene glycol monobutyl ether to a highly refined light spindle oil having a viscosity of 55 sec. at 100 F. as' determined by the Saybolt universal viscosimeter. The repellent soprepared will maintain repellence towards stable flies, horn flies and other insects after spraying for as long a time as sprays containing similar concentrations of pine oil and is substantially odorless and will not taint milk when applied to dairy cattle.

In another embodiment of my invention I have prepared an excellent repellent salve by adding 15 per cent by volume of diethylene glycol monobutyl ether to commercial petrolatum and thoroughly mixing the mass until it becomes homogeneous. The salve so prepared will maintain repellence towards flies quite as long'as salves containing similar concentrations of pine oil. In addition my salve as prepared above is substan- 40 tially odorless and possesses a decidedly unpleasant taste which discourages animals from licking areas to which the salve has been applied.

I find that in accordance with my invention an excellent insect repellent spray for household use may be manufactured by adding between 5 and 15 per cent of either diethylene glycol monobutyl ether or diethylene glycol monoethyl ether acetate to alight petroleum naphtha which has been In use refined sumciently'to make it odorless. such a spray is inoffensive to human beings, but is decidedly effective in keeping away many species of insects. 5 My invention is not limited to petroleum base preparations in which diethylene glycol mono- Insoft petroleum waxes 15 butyl ether and diethylene glycol monoethyl ether acetate are the only ingredients. For instance, in some insecticides likelive stock sprays it is desirable to have in petroleum solutions toxic ingredients as well as those exhibiting repellence towards insects, Petroleum base preparations containing pyrethri'ns or other toxicants can be and 15 per cent of diethylene glycol monobutyl ether as an insect repellent.

3. A petroleum jelly containing between 5 and 15 per cent of diethylene glycol monobutyl ether as a repellent.

4. The subject matter of claim 1,-wherein said petroleum fraction is a light spindle oil.

5. The subject matter of claim 2, wherein said petroleum fraction is a light spindle oil.

6. As a new composition of matter of odorless character having strong insect'repellent qualities, a solution in a petroleum fraction of between 5 and l5 per cent of an odorless substance chosen from the class consisting of diethylene glycol monobutyl ether and diethylene glycol monoethyl ether acetate, the petroleum fraction having sufficient solvent power for said substance to make a clear solution with the amount added.

WILLIAM A. SIlVIANTON. 

